Treatment of high concentration methanol wastewater with two-stage and two-phase anaerobic process

Two-stage and Two-phase anaerobic process (TSTP) seeded with granular sludge was taken to treat the high concentration methanol wastewater. T unit of two-stage system was External Circulation anaerobic reactor (EC). Tests show that TSTP process is quick start-up in 71d, and the maximum VFA hydrolytic acidification reactor effluent is 14.6 mmol/L. In the biological process of methanol converts into methane, the production of acetic acids as intermediate product can be ignored and the direct production of methane from methanol is predominant. Under the condition of volume loading 6.56 kgCOD/m(3).d, the COD removal rate of first-order EC reactor is about 85%, and under the condition of volume loading 1.02 kgCOD/m(3).d, the COD remove rate of second-order EC reactor is about 50%. The total COD removal rate of two-stage anaerobic process could arrive to 90-92.5%. When the inflow COD between 7000-11000 mg/L, its effluent COD is lower than 600 mg/L. Although inflow volume loading fluctuated strongly, TSTP process shows well ability resisting shock loading.